Sofa



FIG. 1 is a front perspective view of a sofa in accordance with the new design;

FIG. 2 is a top perspective view thereof;

FIG. 3 is a back perspective view thereof; and,

FIG. 4 is a left side elevation view, the right side elevation view being a mirror image thereof.

Broken lines shown on the sofa are understood to represent stitching. 

The ornamental design for a sofa, as shown and described. 